Malicious PDF — malware analysis report

Static analysis result for SHA-256 ee4c273a3adb9801…

MALICIOUS

PDF

80.9 KB Created: 2021-09-14 12:17:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 50f081e15410e22f8e976bc8bc597b30 SHA-1: 73223d29d7e23e5b18fb2d4ff42e7f18207235ce SHA-256: ee4c273a3adb980174bb8365e5e50fb145b9591c2221ea712c0678fca711d3d5
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with many embedded URLs pointing to potentially malicious PDFs, and a specific rule identified a 'password-protected archive handoff' lure. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather to host links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Password-protected archive handoff high SE_PASSWORD_ARCHIVE_LURE
    Document gives password instructions for an archive or attachment — often used to keep payloads encrypted until after gateway scanning
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://deforma.it/userfiles/files/59435793904.pdf In PDF document text
    • http://4seasonstours.in/userfiles/file/bawebomoxilore.pdfIn PDF document text
    • http://iweldbot.com/ckfinder/pho/files/demezawevuvoxalirona.pdfIn PDF document text
    • http://dwornawodzie.pl/userfiles/file/65409795785.pdfIn PDF document text
    • https://paymentor.nl/uploads/file/96919991431.pdfIn PDF document text
    • https://nirkongrp.com/ckfinder/userfiles/files/pumadumeser.pdfIn PDF document text
    • https://nguyenvanhuongloc.vn/app/webroot/files/images/pages/files/58296522273.pdfIn PDF document text
    • http://dymenahealthcare.com/upload/fckeditor/file/48690393396.pdfIn PDF document text
    • http://szjwwj.com/userfiles/file///texekuxexesul.pdfIn PDF document text
    • http://tdbakademi.org/userfiles/files/runajal.pdfIn PDF document text
    • http://networkinglikepro.com/ckfinder/userfiles/files/gizupi.pdfIn PDF document text
    • http://xnucleus.com/members/member_images/files/54252926525.pdfIn PDF document text
    • http://i-akparat.kz/ckfinder/userfiles/files/30597799361.pdfIn PDF document text
    • https://master.plus/wp-content/plugins/super-forms/uploads/php/files/000e70c4a4767361d1205931285f3a2a/givupekotulibofufi.pdfIn PDF document text
    • https://n-zvuk.ru/upload/file/tofedazetopidufokofor.pdfIn PDF document text
    • https://kar360.com/resimler/files/tonefewofugikasilalegubaw.pdfIn PDF document text
    • http://xn--e1aazeoc7d.xn--p1ai/images/shared/file/84361843507.pdfIn PDF document text
    • https://plagij.at/ckfinder/userfiles/files/4970411938.pdfIn PDF document text
    • https://amesmedicalservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e7b333b4a9---xebarajel.pdfIn PDF document text
    • http://elfobchod.cz/foto/Image/file/polegagimivirerip.pdfIn PDF document text
    • https://petek.biz/resimler/files/xefipemopidesavew.pdfIn PDF document text
    • https://www.le-domaine-de-hauterive.fr/ckfinder/userfiles/files/85852556490.pdfIn PDF document text
    • https://nutricount.cz/UserFiles/File/nobagulexewogatow.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=how+to+make+a+wifi+hotspot+on+androidPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d62a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD62A 10888 bytes
SHA-256: 873553d66283d2109578af971dfea32e3ad0f79298246bcc9a0b213cd4a3d482
font_01_sfnt_off0000ef2a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF2A 18192 bytes
SHA-256: 72961ad2bbfc34333efa79dd78467f33d74c077906e3860b7275575b6de6c2fe
font_02_sfnt_off00011e0e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E0E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1